The query that gets run to find the most recent tasks is slower for KB articles that are attached to a higher count of tasks:

Resolution

Workaround #1

Set the glide.knowman.recent_tasks.display system property to false to completely disable listing the tasks to which articles have been attached.

Workaround #2

Enable versioning; this may improve the query by adding filters on the kb_knowledge.summary and kb_knowledge.sys_created_on

Workaround #3

Customize the code for the UI macro and filter out the top KB articles by task count (eg., add an additional filter before the "tasks.query();" call in the UI macro to filter out these top 10 KB articles)